Nanoscopic protein motion on a live cell membrane

Cellular functions are dictated by the intricate motion of proteins in membranes that span across a scale of nanometers to micrometers, within a time-frame of microseconds to minutes. However, this rich parameter of space ...

Engineers design solutions to tackle low-frequency noise

Low frequency noise (500 Hertz and lower), which could stem from various sources such as construction machineries and aircrafts, is a form of environmental noise problem in urban environments. Such noise transmits over long ...

Restaurant acoustics that schmeckt

Acoustics consultant Klaus Genuit says that new International Standards Organization guidelines for defining, measuring and evaluating soundscapes are a big step forward in guiding the creation of audibly fine restaurants.

Signals to noise in acoustic vehicles alerting systems

If you've ever wished for a quieter commute, you may be in luck: The low-emission electric vehicles of tomorrow are expected to lower noise pollution as well as air pollution. In Europe, and across the world, the prospect ...

Mapping industrial 'hum' in the US

Using a dense sensor network that scanned the United States between 2003 and 2014, researchers have identified areas within the country marked by a persistent seismic signal caused by industrial processes.

Watching molecules split in real time

Using a new X-ray technique, a team of researchers was able to watch in real time as a molecule split apart into two new molecules. The method could be used to look at chemical reactions that other techniques can't catch, ...

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Noise

In common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise ("static") heard when listening to a weak radio transmission with significant electrical noise. Signal noise is heard as acoustic noise if the signal is converted into sound (e.g., played through a loudspeaker); it manifests as "snow" on a television or video image. High noise levels can block, distort, change or interfere with the meaning of a message in human, animal and electronic communication.

In signal processing or computing it can be considered random unwanted data without meaning; that is, data that is not being used to transmit a signal, but is simply produced as an unwanted by-product of other activities. "Signal-to-noise ratio" is sometimes used to refer to the ratio of useful to irrelevant information in an exchange.

In biology, noise can describe the variability of a measurement around the mean, for example transcriptional noise describes the variability in gene activity between cells in a population.

In many cases, the special case of thermal noise arises, which sets a fundamental lower limit to what can be measured or signaled and is related to basic physical processes described by thermodynamics, some of which are expressible by simple formulae.

In some fields, noise means unwanted information or data that is not relevant to the hypothesis or theory being investigated or tested.

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